In related art, a technology has been proposed that tracks an identical subject that appears in a plurality of images, on the basis of the images that are arranged in chronological order in order to detect an object that moves in monitoring area and identify a gesture.
For example, in Japanese Laid-open Patent Publication No. 2010-74315, a technology is discussed by which a portion area is tracked between the image frames by detecting a portion area that corresponds to a portion area on a current image frame, which is a tracking target on a previous image frame, on the basis of degrees of correlation in portion areas of a plurality of images frames.
In addition, in Japanese Laid-open Patent Publication No. 2011-192090, a gesture recognition device is discussed that recognizes a gesture from a behavior of a recognition target that appears in a video. The gesture recognition device detects a specific subject that appears in a video, calculates a moving speed per unit time of the specific subject, and extracts a movement pattern of the specific subject. In addition, the gesture recognition device identifies the movement of the specific subject as an instruction that is input to the device when the moving speed and the movement pattern satisfy conditions that are defined beforehand.